Celebrity chef Jamie Oliver has challenged Deputy Prime Minister Nick Clegg to make a personal commitment to reducing childhood obesity by 5% within five years.

Oliver, who adopted the 5% target as a personal commitment as part of the annual Food Revolution Day last month, issued the challenge in a recorded message on the Deputy PM's Call Clegg radio show on LBC 97.3.

Mr Clegg said that his pledge of free school meals for infant pupils should help improve children's diets, but declined to commit himself to a particular target - suggesting that 5% may not be enough.

In his message, Oliver asked Mr Clegg: "Is he prepared in his unique position to personally stand up and say he is truly committed to reducing childhood obesity by 5% in five years? Could he possibly get others within the Government to do the same?

"Because I think to do anything less would be morally wrong."

Mr Clegg responded: "What I would say to Jamie - and I would love to talk to him about this one day - is that I think one of the biggest things that we are going to do in the coming months to really try to improve things for children is by providing free school meals to all little kids in the first three years of school.

"The evidence on this is that we have got far too many kids who are poor but not receiving free school meals turning up at school with a can of something and a piece of white bread with chocolate spread on it and they are failing to concentrate in the afternoon, their education is suffering and their health is suffering and they are on the early steps towards obesity."

Asked if he would back Oliver's target, Mr Clegg said: "Whether it's 5%, whether it's 7%, I can't pluck a percentage out of thin air. Maybe we should go for more than 5%.

"All I know is what I can do about this is try to ensure that this new radical policy... is as fully and properly delivered from this autumn as possible, because I think that will help deal with childhood obesity."